Circuit breaker



Nov. 20, 1934. H. 1.. HARTZELL 1,981,042

CIRCUIT BREAKER Filed March 7, 1932 Patented Nov. 20, 1934 UNITED STATES P ream-- 1,9s1,o4z

CIRCUIT BREAKER Herman L. Hartzell, Anderson, Ind., assignor, by

mesne assignments," to General Motors Corporation, Detr0it,-"Mich.,

ware

a corporation of Dela- Applicaticn Mar-eh 7, 1932, Serial No. 597,317

23 Claims. 401. 200 21 This invention relates to periodic circuit breakers particularly circuit breakersused as ignition timers for internal combustion engines.

It is one of the objects-of the present invention to. provide a circuit breaker which will operate satisfactorily at relatively high speeds and this object is accomplished by a combination of ele ments which will be described with reference to the accompanying drawing.

. Further objects and advantages of the present invention will be apparent frcmthe following description, reference being had to the accom panying drawing, whereina preferred embodimentoi one form of the present invention is clearly shown.

In the drawing:

Fig. l is afragmentary plan view of a form of the present invention.

Fig. 21s a side view of the interrupter showing the interrupter housing in section.

Fig. 3 is a side view of the circuit breaker lever looking in the direction of the arrow 3 of Fig. 1, Fig. 3 being drawn to a larger scale:

Fig. 4 is a plan View of a lever shown in Fig. 1 and is drawn to the same scale as Fig. 3.

Fig. 5 is a sectional view on the line 55 of Fig. 4.

Fig. 6 Fig. 1.

Fig. 7 Fig. 3.

Fig. 8 Fig. 1.

In the drawing, designates a housing enclosing a mounting plate 21 having a central aperture 22 through which a cam 23 maybe extended. The cam 23 is driven by a shaft 24 in any suitable manner (not shown).

The plate 21 supports a unitary sub-assembly comprising a bracket 30, insulatingly supporting a bracket 31 carrying a relatively stationary contact 32 engageable with a relatively movable contact 33 and carrying a screw 34 by which a flexible conductor 35 may be attached to a terminal 36 insulatingly supported by the housing 20.

The unitary sub-assembly includes a lever 40 comprising a rigid portion 41 integral with a leaf spring portion. 42 having a slot 43 for receiving a screw 44 by which one end of the spring 42 is attached to an car 45 of a bracket 46 having also an ear 47 providing a fulcrum member 48 which is a sectional view on the line 66 0f is a sectional view on the line '77 of is a sectional view on the line.88 of engages the lever 40 at the juncture 48a between the leaf spring 42 and rigid portion 41. The spring 42 serves to maintain the lever upon its fulcrum 48, the contact between the lever 40 and its fulcrum 43 being a line substantially parallel to the axis of the cam 23. vThe spring 42 serves to urge the lever 40 counterclockwise with respect to its fulcrum 48 as viewed in Fig. 1

in order to urge the rubbing block 49 carried by the lever toward the cam 23 and to urge the relatively movable contact 33 carried by the lever into engagement with a stationary contact 32.

The relatively rigid portion 41 of the lever 40 is formed by folding, as shown particularly in Fig. 3, a portion of metal which originally was of the samewidth as the leaf spring portion 42.

2'Ihat portion to which the rubbing block 49 and contact 33 are attached is of double thickness of metal comprising laminations 41aand 41b foled at 41c as shown in Fig. '7. The rubbing block 49 is formed preferably by molding bakelite or other plastic molding compound against the lever 41, a portion of the rubbing block material being forced into a hole 41d in the lever portion 41. The extremities of the laminations 41a and 4122 are provided with oppositely extending cars 50 lying in the same plane and providing a surface to which the contact 33 is attached preferably by welding. At the juncture of the leaf spring portion 42 with the lever portion 41 the latter is provided with a stiffening rib 51 and the leaf spring portion 42 is reenforced adjacent the juncture 48a by a clip 52 providing the bearing surface'having a portion which partly embraces the portion 42 and which terminates in cars 53 bent around the portion 42 and including the portion which embraces the rigid portion 41 and terminates in cars 54 bent around the flanges 411 of said rigid portion 41. Since the lever 41 is so shaped as to obtain a very rigid construction on one side of its fulcrum and a yielding spring construction on the other side, it is apparent that the lever can be made of very thin sheet steel and hence will be very light in weight and have relatively low polar inertia. Hence the lever is'capable of being operated at a very high. speed without interference to the closing periods of the contacts 32 and 33 due to rebounding of one contact upon the other.

Referring to Figs. 1 and 8, it willbe noted that the mounting plate. 21 carries a stud upon which the brackets 30 and 46 are coaxially pivoted. These brackets are so constructed and arranged and stud 60 is so located that it will provide a coaxial pivotal mounting for the brackets 30 and 46 upon an axis in alignment with the axis for oscillating the lever 40 upon its fulcrum 48.

In order to compensatefor wear of the rubbing block, the entire sub-assembly can be adjusted relative to the stud without changing the relation between the contacts 32 and 33. This adjustment is accomplished first by loosening a screw 61 which directly engages a hole tapped in the plate 21, as shown in Fig. 6, and which passes through an arcuate slot 62 in the bracket 30, said slot being concentric with the stud 60. After the loosening of screw 61, a screw driver blade is applied to a slotted disc 63 located in a slot 64 provided by the bracket 30 and extending radially with respect to the stud 60. The disc 63 has an eccentric shank 65 pivoted in the plate 21. By turning the disc 63 the bracket 30 and hence the entire sub-assembly can be moved about the pivoting stud 60. When the rubbing block 49 has been located in the desired positon to give the correct amount of contact separation, the screw 61 is tightened to clamp the bracket 30 against the mounting plate 21 in the desired position of adjustment.

The bracket 46 is adjustable about the pivot stud 60 for the purpose of adjusting the stress in the spring a2. This adjustment is accomplished first by loosening the screw '70 passing through an arcuate slot 71 coaxial with the pivot stud 60 and threaded into a tapped hole in the plate 30 as shown in Fig. 8. After making the desired adjustment of the bracket 46 to obtain the desired stress in the spring 42, the screw is tightened in order to screw the bracket 46 to the bracket 30 in the desired position of adjustment. The adjustment of the bracket 46 can be secured without affecting the adjustment of the bracket 30 relative to the plate 21; and likewise the adjustment of the bracket 30 relative to the plate 21 does'not affect the adjustment of the bracket it and hence does not affect the stress of the spring 42.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows.

1. A periodic circuit interrupter comprising, in combination, a rotary cam, a pair of cooperating, relatively stationary and movable contacts, a support for the stationary contact, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket attached to the end of the spring, and means for adjusting the bracket relative to contacts.

2. A periodic circuit interrupter comprising, in combination, a rotary cam, a pair of cooperating, relatively stationary and movable contacts, a support for the stationary contact, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket pivotally supported for rotation about an axis substantially in alignment with said fulcrum and attached to the end of the spring, and means for securing the bracket in adjusted position.

A eriodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts. the latter being supported by said plate, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket carrying the fulcrum member and pivotally supported by said plate for rotation about an axis in alignment with the axis of oscillation of the lever upon the fulcrum member, said bracket being fixed to the end of the spring, and means for securing the bracket in the desired position of adjustment.

4. A periodic circuit interrupter comprising, in. combination, a rotary cam, a pair of cooperating, relatively stationary and movable contacts, a support for the stationary contact, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, means for adjusting the initial amount of bending of the spring, and means for adjusting the rubbing block relative to the cam.

5. A periodic circuit interrupter comprising, in

combination, a rotary cam, a pair of cooperating, relatively stationary and movable contacts, a support for the stationary contact, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending fromsaid lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket attached to the end of the spring, means for adjusting the bracket relative to the fulcrum to vary the tension of the spring,

and means for adjusting the rubbing block relative to the cam.

6. A periodic circuit interrupter comprising, in combination, a rotary cam, a pair of cooperating, relatively stationary and movable contacts, a support for the stationary contact, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket pivotally supported for rotation about an axis substantially in alignment with said fulcrum, means attaching the bracket to the end of the spring, means for securing the bracket in adjusted position, and means for adjusting the rubbing block relative to the cam.

7. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, the latter being supported by said plate, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket carrying the fulcrum member and pivotally supported by said plate for rotation about an axis in alignment with the axis of oscillation of the lever upon the fulcrum member, said bracket being fixed to the end of the spring, means for securing the bracket in the desired position of adjustment, and means for adjusting the rubbing block relative to the cam.

8. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket carrying the stationary contact, said bracket being mounted upon a second bracket pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, and means for adjusting said second bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block.

9. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillationof the lever upon its fulcrum, and means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, and means for adjusting the initial amount of bending of the spring.

10. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about an in alignment with the axis of oscillation of the lever upon its fulcrum, means for adjusting-said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, a second bracket attached to the end of the spring and means for adjusting the bracket relative to the contacts.

11. A periodic circuit interrupter comprising, in combination, a rotary earn, a mounting plate, a pair of cooperating relatively movable and static-nary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a leaf spring extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, a second bracket pivotally supported by the mounting plate for rotation about an axis substantially in alignment with the axis of oscillation of the lever upon fulcrum and attached to the end of the spring, and means for securing the bracket in adjusted position.

12. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate. a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, aleaf spr ng extending from said lever, a fulcrum member engaging the lever at the junction thereof with the leaf spring, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon. its fulcrum, means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, a second bracket carrying the fulcrum member and pivotally supported by said plate for rotation about an axis in alignment with the axis of oscillation of the lever upon the fulcrum member, said bracket being fixed to the end of the spring, and

means for securing the bracket in the desired position of adjustment.

1.3.. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and sta tionary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a spring for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward the contact and earn respectively, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about axis in alignment with the axis of oscillation of the lever upon its fulcrum, and means for adjusting said bracket relatively to the mounting plate in order to adjust the distance between the cam and rubbing block.

14. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a spring for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward the stationary contact and cam respectively, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, and means for adjusting the stress in said spring.

15. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a leaf spring extending from the fulcrumed portion of said lever for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward the stationary contact and cam respectively, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, and a second bracket pivotally supported by the mounting plate coaxially with respect to the first bracket and attached to said spring, and means for securing the second bracket in adjusted position.

16. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a call -engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a spring for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward the 'ationary contact and cam respectively, a bracket carrying the fulcrum and the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, and means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block.

17. A periodic circuit interrupter comprising, in combination, a rotary earn, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a spring for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward. the stationary contact and cam respectively, a bracket carrying the fulcrum and the stationary contact and pivotally supported by the mounting plate for rotation. about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, means for adjusting said bracket relative to the. mounting plate in order to adjust the distance between the cam and rubbing block, and means for adjusting the stress in said spring.

18. A periodic circuit interrupter comprising, in combination, a rotary earn, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a leaf spring extending from the fulcrumed portion of said lever for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward the stationary contact and cam respectively, a bracket carrying the fulcrum and the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, and means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block.

19. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a leaf spring extending from the fulcrumed portion of said lever for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward the stationary contact and cam respectively, a bracket carrying the fulcrum. and the stationary contact and pivotally supported by the mounting plate for rotation about axis in alignment with the axis of oscillation of the lever upon its fulcrum, means for adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, and means for adjusting the stress in said spring.

20. A periodic circuit interrupter comprising, in combination, a rotary cam, a mounting plate, a pair of cooperating relatively movable and stationary contacts, a lever carrying the movable contact and a cam-engaging rubbing block, a fulcrum providing substantially a line contact with the lever, a leaf spring extending from the fulcrumed portion of said lever for urging the lever against its fulcrum and for urging the movable contact and rubbing block toward the stationary contact and cam respectively, a bracket carrying the stationary contact and pivotally supported by the mounting plate for rotation about an axis in alignment with the axis of oscillation of the lever upon its fulcrum, meansfor adjusting said bracket relative to the mounting plate in order to adjust the distance between the cam and rubbing block, a second bracket supported upon the first bracket and pivoted coaxially with respect to the first bracket and attached to said spring, and means for securing the second bracket to the first bracket in adjusted position.

21. A periodic circuit interrupter comprising, in combination, a rotary cam; a mounting plate; and a unitary sub-assembly supported by the mounting plate, said sub-assembly comprising a bracket, a fulcrum member, a lever having substantially a line contact with the fulcrum member, and carrying a cam-engaging rubbing block, cooperating contacts carried by the lever and bracket respectively, and a spring for urging the lever against its fulcrum and for urging the rubbing block and movable contact toward the cam and stationary contact respectively; means provided by the plate for pivoting the bracket upon an axis in alignment with the axis of oscillation of the lever upon the fulcrum; and means for securing the bracket to the plate in the desired position of adjustment relative to said pivoted means.

22. A periodic circuit interrupter comprising, in combination, a rotary cam; a mounting plate; and a unitary sub-assembly supported by the mounting plate, said sub-assembly comprising a bracket, a fulcrum member, a lever having substantially a line contact with the fulcrum memher, and carrying a cam-engaging rubbing block,

cooperating contacts carried by the lever and bracket respectively, and a spring for urging the lever against its fulcrum and for urging the rubbing block and movable contact toward the cam and stationary contact respectively; means for adjusting the stress in the spring; means provided by the plate for pivoting the bracket upon an axis in alignment with the axis of oscillation of the lever upon the fulcrum; and means for securing the bracket to the plate in the desired position of adjustment relative to said pivot means.

23. A periodic circuit interrupter comprising, in combination, a rotary cam; a mounting plate; and a unitary sub-assembly supported by the mounting plate, said sub-assembly comprising a bracket, a fulcrum member, a lever having substantially a line contact with the fulcrum member and carrying a cam-engaging rubbing block. cooperating contacts carried by the lever and bracket respectively, a leaf spring extending from the fulcrumed portion of said lever for urging the lever against its fulcrum and for urging the rubbing block and movable contact toward the cam and stationary contact respectively; and a second bracket attached to the leaf spring and resting upon the first bracket; a stud provided by the plate for pivotally supporting both brackets upon an axis in alignment with the axis of oscillation of the lever upon the fulcrum; means for securing the first bracket to the plate in the desired position of adjustment relative to said stud; and means included in the sub-assembly for securing the second bracket to the first bracket in the desired position of adjustment relative to said stud.

HERMAN L. HARTZELL. 

